Control method, mode selection method, transmitting module, and system of signal transmission

Abstract

Provided are control method, mode selection method, transmitting module, and system of signal transmission. The method includes the control unit selecting target control mode from the first control mode and the second control mode according to the working condition of transmitting module. If the first control mode is selected, the electromagnetic interference of transmitting coil is reduced by adjusting the working cycle of control signal to change synchronously, when the level value of first driving signal is valid and the second driving signal jumps once each time. If the second control mode is selected, the quick control of coil current is realized by controlling one control signal to maintain at low level, and the other control signal to switch to low level when the coil current is larger than first current threshold, or to switch to high level when the coil current is smaller than second current threshold.

1 . A control method of signal transmission, applied to a transmitting module in a signal transmission system, wherein the transmitting module comprises: a control unit, a full-bridge power unit, a transmitting coil, and a current detecting unit, wherein the transmitting coil is connected between midpoints of two bridge arms of the full-bridge power unit, and a current sampling point of the transmitting coil is connected to the control unit through the current detecting unit; and the method comprises:
 producing and outputting two control signals by the control unit according to two driving signals, and controlling the full-bridge power unit according to the two control signals to generate a coil current by the transmitting coil, wherein frequencies of the two control signals are higher than the two driving signals, and duty ratios of the two control signals are different; and when a level value of a first driving signal is valid and a second driving signal jumps once each time, a working cycle of the two control signals changes once synchronously;   outputting an overcurrent signal to the control unit when the current detecting unit detects that the transmitting coil is in overcurrent; and   switching the duty ratios of the two control signals by the control unit according to the overcurrent signal, and reducing the coil current according to switched two control signals to adjust a signal to be transmitted.   
     
     
         2 . The method according to  claim 1 , wherein the step of producing and outputting two control signals by the control unit according to two driving signals comprises:
 producing and outputting the two control signals by the control unit, when the level value of the first driving signal is valid and the second driving signal is at a low level, wherein a duty ratio of a first control signal is larger than a duty ratio of a second control signal.   
     
     
         3 . The method according to  claim 2 , wherein the step of producing and outputting the two control signals by the control unit, when the level value of the first driving signal is valid and the second driving signal is at a low level comprises:
 producing and outputting the two control signals by the control unit according to different working cycles, during a plurality of periods when the level value of the first driving signal is valid and the second driving signal is at a low level.   
     
     
         4 . The method according to  claim 1 , wherein the step of producing and outputting two control signals by the control unit according to two driving signals comprises:
 producing and outputting the two control signals by the control unit, when the level value of the first driving signal is valid and the second driving signal is at a high level, wherein a duty ratio of a first control signal is smaller than a duty ratio of a second control signal.   
     
     
         5 . The method according to  claim 4 , wherein the step of producing and outputting the two control signals by the control unit, when the level value of the first driving signal is valid and the second driving signal is at a high level comprises:
 producing and outputting the two control signals by the control unit according to different working cycles, during a plurality of periods when the level value of the first driving signal is valid and the second driving signal is at a high level.   
     
     
         6 . A control method of signal transmission, applied to a transmitting module in a signal transmission system, wherein the transmitting module comprises a control unit, a full-bridge power unit, a transmitting coil, and a current detecting unit, wherein the transmitting coil is connected between midpoints of two bridge arms of the full-bridge power unit, and a current sampling point of the transmitting coil is connected to the control unit through the current detecting unit; and the method comprises:
 producing and outputting two control signals by the control unit according to two driving signals, and controlling the full-bridge power unit according to the two control signals to generate a coil current by the transmitting coil, wherein when a level value of a first driving signal is valid and a second driving signal jumps once each time, an initial level of the two control signals switches once;   outputting an overcurrent signal to the control unit when the current detecting unit detects that the coil current is larger than a first current threshold;   controlling a control signal of a high level to jump to a low level by the control unit according to the overcurrent signal, maintaining a level of a control signal of a low level unchanged, and controlling the full-bridge power unit to reduce the coil current according to new two control signals to adjust a signal to be transmitted;   outputting an undercurrent signal to the control unit when the current detecting unit detects that the coil current drops below a second current threshold; and   controlling the control signal which jumps to the low level to jump to a high level again by the control unit according to the undercurrent signal, maintaining the control signal of the low level at the low level continuously, and controlling the full-bridge power unit to increase the coil current according to new two control signals to adjust the signal to be transmitted again.   
     
     
         7 . The method according to  claim 6 , when the level value of the first driving signal is valid and the second driving signal is at a low level, a first control signal of the two control signals is at a high level and a second control signal is at a low level; and a step of controlling a level jumping of the control signal of the high level by the control unit according to the overcurrent signal, maintaining the level of the control signal of the low level unchanged comprises:
 controlling the first control signal to jump to a low level by the control unit according to the overcurrent signal, maintaining the second control signal at the low level; and   the step of controlling the control signal which jumps to the low level to jump to a high level again by the control unit according to the undercurrent signal, maintaining the control signal of the low level at the low level continuously comprises:   controlling the first control signal to jump to the high level again by the control unit according to the undercurrent signal, and maintaining the second control signal at the low level continuously.   
     
     
         8 . The method according to  claim 6 , when the level value of the first driving signal is valid and the second driving signal is at a high level, a first control signal of the two control signals is at a low level and a second control signal is at a high level; and a step of controlling a level jumping of the control signal of the high level by the control unit according to the overcurrent signal, maintaining the level of the control signal of the low level unchanged comprises:
 controlling the second control signal to jump to a low level by the control unit according to the overcurrent signal, and maintaining the first control signal at the low level; and   the step of controlling the control signal which jumps to the low level to jump to a high level again by the control unit according to the undercurrent signal, maintaining the control signal of the low level at the low level continuously comprises:   controlling the second control signal to jump to the high level again by the control unit according to the undercurrent signal, and maintaining the first control signal at the low level continuously.   
     
     
         9 . A selection method of signal transmission control mode, applied to a control unit in a transmitting module, wherein the transmitting module comprises a control unit, a full-bridge power unit, a transmitting coil, and a current detecting unit, wherein the transmitting coil is connected between midpoints of two bridge arms of the full-bridge power unit, and a current sampling point of the transmitting coil is connected to the control unit through the current detecting unit; the signal transmission control mode comprises a first control mode and a second control mode; and the method comprises:
 selecting a target control mode from the first control mode and the second control mode by the control unit according to a working condition of the transmitting module, wherein   when the target control mode is the first control mode, the control unit is configured to perform the control method of signal transmission according to  claim 1 ; and when the target control mode is the second control mode, the control unit is configured to perform the control method of signal transmission according to  claim 6 .   
     
     
         10 . A transmitting module, wherein the transmitting module comprises a control unit, a full-bridge power unit, a transmitting coil, and a current detecting unit, wherein the transmitting coil is connected between midpoints of two bridge arms of the full-bridge power unit, and a current sampling point of the transmitting coil is connected to the control unit through the current detecting unit; and the transmitting module is configured to perform the control method of signal transmission according to  claim 1 , or to perform the control method of signal transmission according to  claim 6 . 
     
     
         11 . A signal transmission system, wherein the signal transmission system comprises a receiving module and the transmitting module according to  claim 10 .